LOS ANGELES  Researchers scouring the remote forests of the African island nation of Madagascar have found that tiny assassin spiders, grotesque-looking bugs that prey on other spiders, are more diverse than previously thought.

The newly discovered species could shed light on how assassin spiders evolved, and perhaps point scientists to other places in Madagascar where other types could be located.

Scientists from the California Academy of Sciences in San Francisco and researchers in Madagascar caught more than a million bugs, including the nine new species of assassin spiders, during a four-year expedition through the island's rain and deciduous forests.

The bizarre-looking assassin spiders were once widely found around the world, but now are found in Madagascar, Australia and South Africa. About a dozen species of assassin spiders were previously discovered.

Assassin spiders, which grow to less than an eighth of an inch long, are notorious for stabbing helpless spiders with their sharp, venom-filled fangs attached to their super-sized jaws. Assassin spiders also possess very long necks so they can attack their prey from a distance.

They do not spin webs to entrap their prey and they pose no threat to humans, said Charles Griswold, a curator at the academy.

Some assassin spiders will be shipped to a museum in Madagascar and others will be preserved for future study, Griswold said.